Well no wonder I was feeling in the wars! A trip to the GP this morning confirms I've had a virus/infection for at least a week and probably went out to start the race with it! That explains the coughing, bad chest, coughing up bloody fleshy bits etc. and general feeling of a stinking cold. Anyway, I now have more meds to take for a week!

The stomach acid problems though were on top of the infection. The reasons for that are still unclear though likely to do with my electrolytes or food plan or a combination. I will at some point take a trip to the UK's Porsche Human Performance Laboratory to get to the bottom of that issue for the future.

Many thanks to all who were keeping an eye out and asking after me during the event, especially Ian (USA) whose donation of a peanut and raisin oatmeal breakfast on Stage 5 was very welcome, Chris, Sarah & Tom, Ryo, Mickey, Janine and Victoria, Sam Fanshawe and countless others.

Very best of luck to all for future events; I'm sure we'll be racing past each other at some point.

In those immortal words . . . I'll be back . . .

Of all the races I've ever done this was only my second ever DNF.

The plan for the week had been to get a top third place (position 60-65ish), which meant getting a good Stage 1 result and letting that soak up the inevitable declines in the following Stages.

On Stage 1 I finished 51st and by the morning of the Stage 5 start, the Long March, I was at 75. But this Stage was exactly what I'm used to from training in the Yorkshire Dales: rocks, stones and inclines. So I was confident of being able to pick up between 10 and 15 places by the end of the Stage.

But, as you'll know from the earlier posts, my stomach has been playing up. When I woke up Thursday morning I had been low on food for a few days and trying to keep down breakfast without acid reflux from my stomach was a real challenge. Even taking water was now unpleasant. And forget the electrolytes: on Stage 4 just after passing two beautiful rock bridges I took another electrolyte tablet and was sick as soon as it went into my mouth. My body had had enough of electrolytes. The problem is that electrolytes are needed to keep the body's minerals in check during sweating and food obviously is needed for the energy to keep going.

So by the morning of Stage 5 my body was now starting to say "No more!" I did though still feel confident about ploughing on.

Because of the difficulty of getting any support into the canyon CP1 Stage 5 was just a few volunteers with a clipboard. I'd whipped this first 7 miles and descended quickly into the canyon, feeling good. Not for long. The cool, narrow canyon opened out as its 20km (12 miles) rolled on. With it, a strong sun started making life difficult. I tried a couple of jelly babies and felt the acid burn from my throat down to my stomach, which was now also burning and very tender. The idea of giving it my day's supply of beef jerky and salted cashew nuts was not attractive.

CP2 arrived and I just had to sit down. I asked for more meds. She knew exactly what to give me (they were used to it by now): "You're looking very green again, like yesterday." This time the meds weren't working (previously they'd worked until the next checkpoint when I took some more), which was a concern.

The heat climbed, as did the rocky terrain steeply to the top of a gorge. I was suffering now. I was having to stop often on a rock to retch violently but I was not producing anything other than burning my throat: my stomach had nothing in it but acid and meds. My heart rate was also now suddenly spiking quite severely, which it hadn't done all week: another warning sign. Many competitors kindly stopped to ask if I were OK and try to give help.

18 miles covered: just 0.5 mile or so to CP3 to rest a bit. I slumped into a chair at CP3 and Dr. Rob knew what was going on. I decided to rest for 30 minutes. Rob gave me some Pepsi which allowed me to get rid of some of the acid reflux. I tried some of my food: no luck. I tried some more meds. No luck. After 30 minutes I convinced myself I could carry on the 5.5 miles to the next checkpoint, another dent in the day and use CP4 to rest again. But this time even the simple act of walking was causing my stomach to burn.

After 0.2 miles from leaving CP3 I stopped and remembered what the organisers had said at the beginning of the race: it could take at least 3-4 hours to get medical help.

I was about to set off to begin climbing a canyon; the previous one had pasted me. I couldn't eat. I couldn't drink. I wasn't going to last much longer. From my stomach to my throat was just burning and it felt awful.

I turned back to CP3 and I asked what was going on, as I'd used my electrolyte and food plan previously without problems. The answer was honest: "Your stomach is eating itself." Which felt as grim as it sounds. A piece of my stomach had already either broken loose and worked its way up, causing the constant acid, or I was on the way to giving myself a stomach ulcer if I carried on.

Either way, all the signs were that it was my stomach breaking down. My mind was fine, as were my legs, as was my heart rate, and I had zero blisters. But with the choice between ploughing on regardless and causing myself permanent physical damage or quitting the race there was only one option.

So I quit at CP3, Stage 5. I slept on the sand in a blanket, joined later by the sweeper camels, until the CP closed and we could move off. The 4x4 journey out of the desert was fun, having to stop along the way for more retching sessions. Sam (one of the course organisers) caught up with me at CP6 where we'd stopped to drop off kit and said they were all surprised to see me having got this far: they knew my stomach problems had started on Stage 2 or 3. I also learnt here that our tent's star competitor had had to quit too just two CPs short of the finish because of an inability to take food or water; others I know have also fallen out but for obvious reasons I don't want to be publishing their names here as the organisers might not have published the results list yet.

No tears, no regrets. Which means this was entirely the right and sensible decision to make.

It's now 7pm Friday (I quit 2pm-ish Thursday) and I've now got some solid real food down me, slept a bit but still getting the odd acid/stomach problem. Everything should be fine with no permanent damage. I weighed myself as soon as I got back to the hotel and in 5 race days I've lost 1 stone, 1 pound . . . which is a lot in 5 days!

Thank you everyone for all of your comments and kind words, which I've read avidly after each Stage: you won't believe what a difference it made!

After 95 miles now covered there’s really only the Long March to go: 54 miles with just over 2,000 metres of ascent, tomorrow.

Not feeling at all well today. From yesterday morning had awful acid reflux going on. Told it’s because of too many electrolytes. Given a few tablets which worked a short while. Still can’t rehydrate properly: only pee’d 4 times since last night despite 6 litres of water. Woke up this morning and only just managed to get to the start line on time because painful cramping on my forearms and fingers: lack of electrolytes. So planned to take it real easy for today’s Stage 4.

Went through a cycle of either feeling sick or oesophagus feeling bad. Vomited twice before CP2. Hotter than expected. Wondering if I’ve simply had too few calories as well as problems going on with my water and electrolytes balance. Given more tablets at CP2 which seemed to do something. I could open a chemist with the contents of my stomach, the amount of meds I’ve been having (ignore the fact they’ve dissolved!).

So one long march today with very little running. Still trying to get and keep the water down: have drunk over 3 litres since CP3 (penultimate CP to finish).

The only goal tomorrow then is simply to finish the 54 miles and if that means resting often I’ll have to. My stomach isn’t behaving as it should be and it’s a bit miserable! Oh, and very bright: lost my sunglasses within the first 2 miles of Stage 2 and today very warm and strong sun.  

Noah, Zoe & Rhys: no new animals today but lots of insects. Crossed into a new sandy desert today and saw lots of viper holes, though no vipers. Towards the end we had to get on our hands and knees to crawl through a low tunnel for 25 metres: it was full of sand and goat droppings. Yuch!!!

I’d used sleeping tabs on first 2 nights, which didn’t work. They’ve handed out blankets now so last night much better sleep after 2 cocodamol. Maybe 4 hours sleep?

Getting a bit chin-strapped now. Can’t rehydrate properly so took it a little easier on Stage 3 which I finished a couple of hours ago. That’s 70 miles now covered in 3 days so almost half distance.

Amazingly no blisters, yet, but likely to lose two nails and may need 1 drilled: will see how it goes. Have now reached the point where flies find me very attractive.

My legs are talk of the camp. Duncan (UK): “Your calves are bigger than my thighs!” Ian (USA): “Man, those are monster-truck-tyres you’ve got on your legs there” and today he kindly gave me a couple of sweet bars, “You need to feed those legs!” Tony Brammer who mans CP3: “Ah! That must be Mark. I’d recognise those legs anywhere.”

The legs didn’t feel too full of energy today though. Just felt mildly nauseous and bile reaction; trying hard to get the water down enough so I can pee (meaning I then have excess water and am hydrated): only going once a day!

Will reserve energy tomorrow in prep for the Long March (56 miles). All a bit worried about it: an overnight finish in all our kit to keep warm will mean a chilly finish trying to get warm in the sleeping bag.

Noah, Zoe & Rhys: saw a camel racing track today and lots of camels. I even saw a baby camel that had just that second been born! Finding it tough at the moment as difficult to drink enough without feeling ill. Did you know the Japanese don’t have toilets? A Japanese competitor in my tent (Leo) introduced me to some other Japanese competitors who were all fascinated to know how we in the West do a number 2; they just squat (Daz will show you what that is (!)), which is what I’m having to do over a sandy hole! Yuk! It’s also hard to do. That’s today’s Uncle Mark education lesson over.

Off to drink more! A tad over 30C I hear.

Love you Em!

First 2 nights not good: rain, freezing cold. Last night desperate for warmth even though all kit on. Had to use emergency bivvy blanket so although a little warmer woke up wet as bivvy doesn’t breathe. Spent all afternoon back at camp drying everything. Now have thicker blanket now though from organisers. Hope to get some sleep. Haven’t slept in first two nights.

Good run yesterday but overcooked it? Tough today, long slog up in sand. Feeling sick and crashed. CP3 medic: “Too much electrolyte.” Still trying to rehydrate. Will take it easier tomorrow.

The cold at night is making quite a difference.

Noah, Zoe, Rhys: Noah, did you save me some chips? Saw some camel bones today: some of the faster runners ahead of me get hungry. It’s very cold at night out here. Animals seen today: lizards, butterflies, wild camels, wild dog, dung beetles. Lots and lots of sand.

Need to get a hot meal so off now.

Love you Em.

Amazing scenery on the plane’s descent into Amman. Huge smile on my face being back in the desert!

Check in day has sped past, once I got up. Leo, my Japanese room-mate, asked surprised at 7.40am: “Mark, are you getting up?!?” He’d already been up since before 6.

I seem to have raised too many expectations in other competitors without me saying anything. In the check in room we had to lay out all our kit ready for inspection; I don’t have much. Chris, from the USA, said my small, neat pile looked pretty and he wished I were his friend two weeks ago. My tent mates look on at my small pile of food and can’t believe I only have 14,234 calories for the week. Some have up to 28,000, but with 15kg rucksacks! I’m getting a little worried about it: Lucie (?) from Japan in our tent has 16,500 and she’s whippet-thin. I’ll soon find out if I’ve made a mistake; some night-time food raids might be needed!

Typing this in camp. Dark by 6. Sat by the camp fire eating partly-rehydrated food then it started to rain. My lightweight rucksack is telling: I have my only 3 layers on and I’m still cold! Not so bad once in the tent but it’s traditional Bedouin thread-bare canvas and the rain is dropping in.

Not long been introduced to other tent-mates from Japan. “You fast!”, just from looking at my kit. “No, I’m really not!” I am the only one though sitting in camp shivering a bit and wearing shorts.

6.30 now. Time to get into bed before long.

Noah, Zoe & Rhys: cold and a bit wet. Seen  lots of camels and donkeys, kestrels, sparrows and swallows. And loads of donkeys. Saw two shepherds on one donkey shepherding their goats; they were both bigger than the donkey so looked a bit silly with their legs almost touching the ground. If the donkey had wheels they could scoot!!! Lastly, I won’t now be showering, shaving or cleaning my teeth for a week: how cool is that!!!!

Rain getting harder so off to bed to get warm.

The packing's finally done and my total rucksack weight weighs in at 7.85kg of which about 3.3kg is food. That's a great starting weight and I'm delighted with that. Add on 1.5 litres of water at the start of Stage 1 and my maximum weight carry becomes 9.35kg. I'll still be shattered after the first hour of running across deep sand though!

To trim off almost 350 grammes since the initial weigh-in has taken some effort but it will be worth it (I convince myself). There's not as much comfort as I hoped for so it's going to be a tough week, e.g., I've ditched the sleeping mat to opt for the cold desert floor which hopefully won't be too stony: a thin Bedouin blanket will separate me and my sleeping bag from the sand. Ditching the mat, a small thing that I kept falling off every two minutes anyway last time I used it, alone saved 218 grammes. I couldn't though bring myself to give up the inflatable pillow (yep, I know it doesn't really make a lot of sense!).

I really can't chop off anything else and I don't want to give up my iPod Nano, my personal "Break Glass in Emergency" kit, or my solar charger. The charger is an important bit of kit to keep my Garmin GPS and heart rate monitor charged: the heart rate readings and distance covered are useful tools to keep a check on putting in too much effort too soon. I don't want to end up on an IV drip for 4 hours as on my last desert outing: then it just meant a 2 hour time penalty; for the 4 Deserts races it means disqualification.

I will try and give an update on this blog after each stage finish, sandstorms, failed satellite links, sickness and general lethargy permitting!

It's been that kind of weekend so I can have as stress-free a week as possible: pack, unpack, repack in the never-ending game of trying to get the rucksack weight down.

I'm left with 8.2kg which includes all food and a few luxuries in addition to the mandatory equipment. With at least 1.5 litres of water at the beginning of Stage 1 my maximum rucksack weight should therefore be about 9.7kg, and then rapidly diminishing thereafter as about 400-600 grammes of food alone per day gets consumed.

But how much better it would be (I tell myself) if I could shave off another 201 grammes . . .

Hmmmm . . . . do I really need that inflatable pillow (the answer's "Yes")? Is 16 sheets of toilet paper per day excessive or would 12 do? I've cut down or cut off anything I don't need but I'll be tinkering all week. I'm sure there are a couple of labels I've missed with the scissors.

Unfortunately I can't do anything much more with my food weight. From my last desert jaunt I learnt I didn't need as much food as I took, which was something like 16,800 calories. The race-legal minimum is 14,000: I'm in at a tad over 14,200 . . . mostly down to the weight-to-calorie power ratio of salted nuts or dried fruit and nuts and Expedition Foods' freeze-dried meals (which I actually quite enjoy of all those brands I've tried over time!).

Right, better get those mandatory race patches sewn on my tops . . .

Samantha at Racing the Planet had kindly mentioned that fellow competitors Amjid, Josh and Liz were meeting up on Saturday with Tony Brammer for last-minute tips and hints on the Sahara Race 2014. An opportunity not to be missed! Tony joined the 4 Deserts Club in 2008 having completed all 4 of the 4 Deserts Series yet had only set out to complete one of them . . . Once you're bitten . . !

Fired up by Tony's tales was just what I needed for my last long run so it was a drive down to Worcester yesterday to complete one of the Dawn to Dusk marathons. If it weren't for the fact I had the psychological boost of knowing this was the last of my long training runs for 3 weeks I could easily have bailed: freezing cold and driving rain for the duration and, on the outward section of the course, strong gales.

For technical reasons my 26.2 miles became 27.75 (details in my blog post here) but I still felt strong although sore by the finish. It felt so good to stop, sit, eat and wallow in the knowledge that all the hard training was finished.

And for the last 3 weeks? 30 easy miles per week with a couple of hill repetition sessions thrown in and some gym/core stability work to top things off.

And packing!

A question I'm often asked . . .

When I climbed the last sand dune to cross the finish line of the Marathon des Sables in April 2012 I was thinking "Never again!"

That thought lasted little more than 10 minutes: once I reflected on a very tough but enjoyably challenging week I realised the race was a springboard . . .

My forthcoming book Running from Shadows mentions the years I'd spent enjoying running in the middle- to back-of-the-pack of marathons, a few ultras and three Ironman triathlons until my career saw the hours spent in the office becoming disproportionate to the time spent outside it. After 4 years of inactivity I felt rough. So I signed up for the MdS. The book describes those experiences and my blog (www.runningfromshadows.com) will pick up where the book stops . . . aiming for my next goals, including joining the 4 Deserts Club.

2012 was a turning point. Coming back from the MdS I resolved to do two things: firstly, to change my career to a subject area I'd always enjoyed and found interesting and, secondly, to change my lifestyle and build on my MdS to continue with the extreme challenges.

As any extreme event veteran will know, and first-timers will shortly find out, there's a huge range of incredible experiences to be had going through the depths of sleep and energy deprivation mixed with unbridled joy running across deserts in beautiful, remote parts of the world. The best description I've heard of this cathartic process is of it being a "life laundry": the white noise of daily life fades away to insignificance in the middle of a sand storm when all you have is on your back and it's pitch black with 20-odd miles to go to the finish line of the 50-odd mile stage . . .

7 days of very basic living with everything I need on my back, the inevitable physical and mental fatigue, the full force of nature, barely enough food to get through the day, amazing scenery, sharing adventure stories and life revelations with like-minded souls . . . to return home and understand again what truly matters . . .

That's why. 26 days to go. I can't wait . . !